How Has the Political Landscape of the South Changed in the Last

How has the political landscape of the South changed in the last 50 years?

A) There has not been much partisan change in the South.
B) The South has gone from being a toss-up to being solidly Democratic.
C) The South has gone from being a toss-up to being solidly Republican.
D) The South has gone from being solidly Democratic to solidly Republican.